For living at home - £200 per month + 1 bill - I think it's important for them to pay a bill in their own name to start building a financial history and being a fully adult part of the household.
Their father and I are still paying everything for our kids within the home and their phones. We don't pay for transport costs unless we're all traveling together as a family after they stop being eligible for the school/student bus tickets. We also don't pay for any additional entertainment for them, but they have access to ours.
My DS1 and DD1 last year both earned more than I did. My DD1 is looking likely to do so again this year. They're aware that when they're paying that £200, it goes into the account that is used to mostly used to pay to family extras for trips and such, and as they're paying in, they're part of the conversation on how that's spent in a way their younger siblings aren't.
I find it particularly odd when people charge their DC who are doing apprenticeships. If they had chosen the uni route, you would have been expected and required to support the costs of doing that.
My DS1 chose the uni route, but as he earned his way onto a sponsored course, he gets a monthly bursary on top of his tuition being paid & he gets paid back his travel costs between the campus and home during breaks. He also worked for a year prior to doing so and is in a financially good place while living in halls. The only cost I've covered is him still being on the family plan for his phone, his share is like £7 a month and he still has access to our Netflix and things.
They are effectively saving you thousands by doing the apprenticeship option, and you are also going to make them give up the pittance of a wage they get.
Not all apprenticeships pay a pittance. A quality employer in a desirable work area and location will pay well above the apprenticeship minimum wage.
My DD1 went the apprenticeship route from 16, and at 16 earned more than I did that year, and she wasn't anywhere near the highest wages for apprentices I've seen. It's very possible for the few who get onto apprenticeship schemes in some engineering or tech companies to be earning over 30k a year plus tuition.
Also, if they can and do take the apprenticeship option at 16, they're no longer considered fulltime students, which means some things do become significantly more expensive earlier than if they took a more academic route. The opticians, as an example, treats 16 year old apprentices on any wage the same as adults. I'm well aware of families that got the sticker shock when their child who used to be covered by the NHS for their eye tests and glasses suddenly wasn't (and because they're at home, they're unlikely to get any additional NHS help for it).
Parents feel a responsibility to look after the DC rather than turning it into a transaction at 18.
I don't see how my kids paying into the household pot that is used for their benefit is turning our relationship into a transaction or mean I'm not looking after them. I see it as treating them like an adult, they pay in, they get to be part of the conversations on household finances.
Having grown up in a culture where kids, particularly girls, do stay at home and get it all paid for as adults until they can move out - I'm well aware of the painful strings that can be attached to that. It isn't all sunshine and roses and unconditional love just because the adult child isn't having to pay. I've been there, done that, fled that.